Is a character expression that contains the sequence to be found. Wildcard characters can be used; however, the % character must come before and follow pattern (except when you search for first or last characters). pattern is an expression of the character string data type category. pattern is limited to 8000 characters.

expression

Is an expression, typically a column that is searched for the specified pattern. expression is of the character string data type category.

If you do not restrict the rows to be searched by using a WHERE clause, the query returns all rows in the table and reports nonzero values for those rows in which the pattern was found, and zero for all rows in which the pattern was not found.

B. Using wildcard characters with PATINDEX

The following example uses % and _ wildcards to find the position at which the pattern 'en', followed by any one character and 'ure' starts in the specified string (index starts at 1):